Spalart Allmaras DDES - circular cylinder
Dear OpenFOAM users,
I want to make some aeroacoustical simulations coupling OpenFOAM with an opensource acoustic simulation code. I am trying to simulate the von-karman vortex street after a circular cylinder at Re=166000. After performing 2D incompressible simulation with pimpleFoam solver and a k-omega SST turbulence model (getting quite good results in term of force Coefficients and Strouhal number), I would like to improve my simulation using the Spalart Allmaras DDES hybrid turbulence model. I made few tests (2D case), but I'm getting a non-physical behaviour (look at the animation). I also attached the case-study folder. I would be very pleased to you if you could get me some suggestions. Thank you very much! 1)DDES case-study: https://mega.co.nz/#!osgCHZYB!Vf4Yxg...TxQfzgX-sgWeGw 2)DDES animation (U magnitude): https://mega.co.nz/#!JlxVQCCI!E0xGLS...cUx-AD5TmCu-1o 3) komegaSST case-study: https://mega.co.nz/#!JgYDwSob!T9EYAl...5bG53ncqcMSWcA 4)komegaSST animation: https://mega.co.nz/#!dkZmmIwB!KVs80U...TtuPfh6eXrYZnQ PS: Sorry , I moved this thread which was previously posted in the wrong section, thanks! |
the website you posted does not work. Your cases can not be downloaded!
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Hello!
I've just checked the links and they work! Can you please specify what kind of problem the browser gives you? Thanks! |
For my browser it needs to set up Flash.
But i have one question about your case. Did you use empty BC with one cell thick domain both in SST and DES case? |
I think that you can't use DDES in a 2D simulation. DDES is a hybrid RANS-LES method in which you should capture the large 3D eddies in the wake. In a 2D simulation you are going to miss the effect of the vortex stretching that is important in the energy cascade process.
Probably this is the explanation for the non-physical results that you got. |
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I was wondering if you have made the SA-DDES model work and for more complicated geometries? If yes, would you mind sharing your discovery? Thanks! |
Hi f0208secretx
Basically, I have to perform a S-A DDES, and I am trying to modify the channel395 tutorial case for the beginning, then I will go to a (very) more complex geometry. I would suggest you to do the same. I will post a tutorial as soon as possible. |
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